Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Design tool beefs up artificial muscles

05.07.2016

Polymeric materials that stretch out when electrically stimulated can benefit from realistic numerical simulations.

Robotic devices are usually composed of hard components such as aluminum and steel, in contrast to the soft tissues that power biological organisms. A study conducted by A*STAR researchers now makes it easier to turn squishy, electroactive polymers into artificial muscles and biomimetic energy harvesters through computer-aided design [1].


A finite element simulation of a viscoelastic dielectric elastomer actuator, which undergoes wrinkling under voltage. © 2016 A*STAR Institute of High Performance Computing

Dielectric elastomers are rubbery, insulating membranes that respond dramatically to electric fields — when sandwiched between two electrodes, they can expand by several hundred per cent in a two-dimensional plane. These special deformation properties have led to applications such as soft-body robotics and sensors. However, the shape-shifting membranes often develop changes in their electrically stimulated response over time, making them hard to optimize for long-term use.

Keith Choon Chiang Foo from the A*STAR Institute of High Performance Computing and his team realized that numerical simulations could help to improve dielectric elastomer devices. They turned to finite element analysis, a tool that predicts the performance of complex objects by modeling them as small interconnected geometric units, to reach this goal. But finding algorithms that replicate smart polymer behavior is not straightforward.

“Existing finite element software doesn’t have the capability to simulate soft rubbery materials that respond to electricity and involve large deformations,” says Foo. “Plus, most simulations of these polymers have been done using ‘in-house’ software, meaning source codes are not available to the scientific community.”

The researchers solved these issues with a model that revealed how repeated movements affected the membrane’s ability to respond to electricity and mechanical forces over time. Their algorithms coupled this property, known as viscoelasticity, to electrostatic charges in the device. They implemented this model into commercial finite element software. “We have made the subroutine freely available to aid other researchers,” adds Foo.

The team’s simulations highlighted examples where viscoelasticity has an impact on the performance of artificial muscle-like devices. For example, when an electrical pulse causes the membrane to stretch out, the elastomer takes a characteristic time to relax to the new configuration. If the pulse cycles at a rate close to this relaxation time, mechanical actuation can be significantly affected.

Further tests showed the improved finite element analysis could quantify the critical time delay between the instant an electrical signal is applied and the maximum polymer actuation achieved. Because the computations agree well with previous experimental data, Foo is confident this technique can reduce trial-and-error approaches to biomimetic devices.

“This simulation tool may prove very capable,” he remarks. “When we work with experimentalists, it helps guide our approach to soft machines.”

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing. For more information about the team’s research, please visit the Soft Matter Group webpage.

Reference

[1] Foo, C. C. & Zhang, Z.-Q. A finite element method for inhomogeneous deformation of viscoelastic dielectric elastomers. International Journal of Applied Mechanics 7, 1550069 (2015).

Associated links

A*STAR Research | Research SEA
Further information:
http://www.researchsea.com

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>